Control of aircraft



June 13, 1939. E WOLF 2,162,150

CONTROL 0F AIRCRAFT Fil'ed June 20, 1936 2 Sheets-Sheet l vJune 13,1939.l

E. woLF CONTROL OF AIRCRAFT Filed June 20, 1936 2 sheets-sheet 2Patented June 13, 1 939 i UNITED STATES PATENT .OFFICE 2,162,151;rcoN'rnor. or AIRCRAFT Application June 20, 1936, Serial No. 86,395 InGermany July 2, 1935 9 Claims. (Cl. 244-84) i engageable connectionsbetween similar parts of My invention relates to the means forcontrolling aircraft and more especially airplanes and other flyingmachines and has for one of its objects to render such control morereliable than hitherto. Y

In airplanes it is known to provide the control stations in duplicateand to connect equal parts, to be operated by the pilot, of 'eachstation with each other and with the other parts of the control in suchmanner that all the control surfaces can be operated either from one orthe other station. This is done before all for the purpose of enabling apilot to be readily replaced by another pilot, quite especially on longdistance flights.

It is further known to provide also the power transmitting membersincluding rods, chains, cables, shafts etc., which extend between thecontrol levers and the control surfaces, in duplicate in order toincrease the safety of flight by guaranteeing a safe control of theairplane also in the case where one of the power transmitting membersmight break or be destroyed by shots etc.

However even such double controls will be rendered inefficient wheneverone of the power y transmitting members orone of the control surfacesshould jam.

In order to avoid all dimculties arising from this' or other accidents,I subdivide, according to the present invention, the entire controlsystem including the control levers, the power transmitti'ng members andthe control surfaces, into two halves in such manner that if any of themembers forming part of one half should break or become useless orinoperable for, some other reason, the craft may be controlled by meansof the corresponding member of the other half.

I therefore subdivide all the control surfaces into two halves, whichare capable of being operated and moved independently from each other.The two part elevators thus provided may be arranged in coaxialjuxtaposition or in parallel superposition. Similarly the part ruddersmay be arranged in coaxial superposition or in parallel juxtaposition. Ifurther provide a separate control station with the necessarycontrolling members (handles, levers and the like)v for each half and Iconnect each control member of one half by means of a separate powertransmission with the corresponding part control surface of the samehalf. I am thereby enabled to at any time operate one half of thecontrol sys- 'temfrom one, the otherhalf from the other control station.,I further prefer providing disthe two halves of the control system.'the arrangement being such that during normal operation all controlsurfaces may be adjusted from one station, while, if any part of onehalf of the control system should become unfit for use,

-this part can be disconnected from this control station and be cut out,if necessary with the other parts to be operated with its aid, whilethatpart of the other half of the control system, which correspondsA tothe cut out part, is still available for the control. In order tofurther increas'e the safety of flight I may further subdividecorresponding members of the two halves of the control system, and moreespecially the power transmitting members and may disengageably couplesuch members with each other by their ends. I may further providedisengageable cross connections between the corresponding members of thetwo halves of the control systemv in such manner, that, if one member ofone half should become unfit for use, its l 'aircraft embodying myinvention are illustrated diagrammatically by way of example.

In the drawings Fig. 1 is a perspective diagrammatic showing y of acontrol system of an airplane.

Fig. 2vis a similar showing of a similar system,

in which however the power transmissions of each half are subdivided andthe divisional members of one half are arranged to be coupled withdivisional members of the other half.

Referring to the drawings and first to Fig. 1, the control system hereshown is subdivided into two halves, each of which forms in itself acomplete control. Two control stations, each provided With the requiredcontrol members, are provided, these control members comprising a rocklever la and Ib for the elevators, a pedal lever 2a and 2b for therudders and a hand wheel 3d and 3b, respectively for the ailerons.

`The elevator is subdivided into the part elevators 20a and 20a, therudder into the part rudders a and 30h. The ailerons are formed in awell known manner by twoV surfaces 40a and 40h rockable inl oppositesense. The part elevators 20a, 20h are connected by means of the 23a,23h and 24a, 2lb, respectively. The part rudders 30a, 30h are connectedby means of the rods-32a, 3217 pivoted to the rudder levers 3| a, 3|bwith lever arms 33a, 33h, which are xed on the pivots 34a, 34h of thepedal levers 2a, 2b. These pivots are supported in bearings' 36a, 35h,respectively, fixed 'on the craft.

The ailerons 40a, 0b are connected by means of, the rods 42a, 42hpivoted to the aileron levers I la, 4Ib with lever arms 43a, 43h, whichare fixed on separate shafts a and Mb, respectively. 'Ihese shafts aresupported in bearings 45a, 45h and 46a, 46h, respectively, fixed ,to thecraft. On the shafts 44a, b are further fixed lever arms 41a, 41h, whichare connected by rods 43a,

l 8b with lever arms 48a, 49h, which are located responding aileron isoperated.

in bearings at thebottom ends of the rock levers la and lb,respectively, their axles carrying sprocket wheels 52a, 52h, which areconnected by means of chains 53a, 63h with the sprocket wheels 54a, '54bfixed to the hand wheels 3a and 3b, respectively, supported by the rocklevers. By turning one of these hand wheels the cor- Between similarcontrol members'and/or part control surfaces of the two halves of thecontrol system couplings are inserted. ,In the elevator control isinserted a clutch consisting of the halves 63, 64 and a' clutchoperating. lever 65 for the* coupling of the 'rock' lever shafts 25a and25h. A similar clutch device 6 6, 61, 68 is provided between the axles26a, 26h of the .part elevators 20a and Zlib, respectively. In theaileron control a similarl clutch device 1|-, 12, 13is inserted betweenthe shafts Ma and Mb. In the rudder control cou pling rods are provided,one of which (36) connects the lever arms "3.1a,31b xed on the pedallever pivots 34a, 34h, respectively, while another coupling rod 38 isattached to pins 33a, 39h of the part rudders 30a, 30h. As a rulethesecouplings and clutch devices are vthrown in and the entire controlsystem may then be operated from one or the other control station.However, when the danger arises that during flight any member `might bedamaged or destroyed, the connections 66, 61 and 38 between the two partelevators and the two part rudders are severed. On the other hand theconnections 63 64 and 1|,- 12 as well as 36 remain at first operativeso'that the craft can be further operated from any one of the twocontrol stations. If now a part. of the system,

` for instance the part ,elevator 20a, should'be rendered inoperative,the consequence of jamming, during flight, the connection between thecorresponding halves (the clutch 63, between the rock levers la and Ibof the part elevators 20a, 20h) is severed and the safe control member(part -elevator 20h) is adjusted by itself from the con.-

trol station (rock lever Ib) apportioned toit.

While the craft is now less readily controllable,

the availablecontrol still suffices toavoid a fall oraforced landing.

If duringthe flight some part of the power transmission, forinstance theelevator rod 22a,

should break, the part "elevator 20a will at first become inoperative.By throwing in thel .clutch 6C, 61 this part elevator can however becoupled with the part elevator 20h and serve further to control thecraft. y

y The control system illustrated in Fig. 2 is similarly subdivided into'two halves, each of which constitutes a complete controlling system.'I'he parts already shown in Fig. 1 are here marked with the samereference numerals. In this modirespectively.

these rods are pivotally inserted the lever arms ncation also thelsingle power transmission systems are subdivided and the members ofthese.

of need, if a power transmitting member of one half of the system shouldbe destroyed, its function can be fulfilled by the corresponding memberof the other half.

` The power transmission to the elevators is here 10 effected by meansof the rods Bla, 8|b and 82a, B2b, respectively, which connect the leverarms 2|a, 2lb fixed to the part elevators 20a, 20h with the rock leversla, Ib. 'I'he adjoining ends of the rods 3| a, Mb and 62a, B2b arepivotally connected 15 to the vlever arms 83a, 83h, which are securedagainst rotation on the shafts 66a, 86h supported in bearings 64a,'84band 66a, 35h, respectively, -fixed to the craft. Between the shafts 86a,86b

is inserted a clutch device 31, 66, which can be 20 thrown .in and cutby means of a lever 89. The power transmission to the part rudders iseffected by means of rods Sila, 9|b and 92a, 92h, which connect thelever arms 3|a, 3| b of the part rudders 30a, 30h with the lever arms33a, 33h secured .25 to the axles 34a, 34h of the pedal levers 2a, 2b,Between the adjoining ends of 93a, 93h of the bell crank levers 33a, 94aand 93h, 94h, respectively, which are supported for rota. 30 tion on thepivot pins 95a, 95h mounted in bear- -ings 96a, 96h fixed' to thefuselage. 'I'he lever arms 94a, 94h of the bell crank levers may beconnected by a coupling rod 91.'

The members forftransmitting powersto the 35 ailerons, which connect thelever arms lla, Hb of the ailerons 40a, lb with the intermediate leverarms 43a, 43h coupled with the control members (hand wheels 3a, 3b) areformed by rods |0|,a, Ilb and |020, |6212, respectively.' 'I'he ad- 40joining ends of these rods are pivotally connected with levers IIIGa,|0611 mounted on the shafts |03a, |031: supported in bearings lilla,|041) and Illia, |0511, -respectively,vwhichare fixed to the craft.Between the shafts ||I3a and |031 is in- 45 serted a clutch |01, 4|03which can be thrown in and out by means of a lever |68.

If, during flight, a member of one of the power transmitting systems,for instance the member 32h of the power transmission to the part ele-50 I vator on the backboard side, should become inf ,operative, the.full control over the craft can be lever Ib of the other controlstation by throwing out the clutch 63, 6I. Besides this the broken^ypower transmitting member 82h may be severed 65 from the other controlmembers connected to it (rock lever' Ib and lever arm 33h). In thismanner the danger is avoided that by a jamming of the broken member theother control members might be immobilized.

In the case that during flight different members of similar parts of thetwo halves of the control system, for instance a member of the powertransmission (such as member 82h .of the elev ator control) in one halfand a control surface (for instance the part elevator lIlia) ofthe otherhalf of the system should be destroyed, it is recommendable to firstconnect the intact parts of' the power transmissions of the two halves(member 82a of the elevator control of one half and member Blb of theelevator control .of the other half) with each other by means of theauxiliary clutch 81, 88 provided between the adjoining ends of the partsof these power transmission systems in such manner that .they nowtransmit power between the rock lever la connected to the intact part82d' of the power transmission and the intact part elevator 20h. Besidesthis the conf nection between the rock levers of the two halves of thecontrol systemmay be severed by throwout the clutch 63, 64.

Thus the control of the control surfaces of the craft is here renderedpossible also in -the case when different members of the two halves ofthe double control system have become'inoperative.

I wish it to be understood that I do not desire to be limited to theexact details of construction shown and described for obviousmodications will occur to a person skilled in the art.

. 1. In an aircraftl having a.- pair of duplicate control surfaces,disengageable coupling means directly operative between said controlsurfaces comprising one clutch element on one said surface and acooperating clutch element on the other said surface, means for readilydisengaging said coupling means, a control member, and powertransmission mechanism between said control member and one of saidcontrol surfaces whereby the other control surface may be actuated bysaid control member or remain inoperative.

2. In an aircraft having two separate control systems, each of whichcomprises a control member, po'wer transmission and a control surface,disengageable coupling means directly operative between said controlsurfaces comprising one clutch element on one said surface and acooperating clutch element on the other said surface, and means forreadily disengaging said coupling means whereby the control surface ofboth systems may be operated from either controlmember.

3. In an aircraft having two separate control systems,feach of whichcomprises a control member, power transmission and a control surface,disengageable coupling means directly operative between the controlsurfaces 'and disengageable coupling means between the powertransmissions for interchangeably operating the control surfaces of eachsystem fromieither or both control, members, said coupling meanscomprising cooperating clutch elements associated with the parts to becoupled, respectively, and means for'readily disengaging each of thecoupling means.

- 4. Mechanism as described 'in claim 3 wherein the power transmissionsbetween the two control members and respective duplicate controlsurfaces are disengageably coupled intermediate the control members andthe control surfaces whereby all control surfaces may be operated fromone control member on breakage oi' the transmission mechanism extendingfromfthe other.

. 5. In an aircraft having two separate control systems, each ofwhichcomprises a control mem' ber, power transmission and a controlsurface, disengageable coupling means directly operative between saidcontrol surfaces and disengageable coupling means directly operativebetween said control members for interchangeably voperating the controlsurface ofv each system from either or both control members, saidcoupling means comprising cooperating clutch elements associated withthe parts to be coupled, respectively, and

means for readily disengaging each of the coupling means. l

6. In an aircraft having two separate control systems each of whichcomprises a control member, power transmission and a control'surface, adisengageable coupling directly operative between thev powertransmissions of the two systems at points intermediate the controlmembers and the control surfaces, and a disengageable coupling directlyoperative between the control surfaces, said couplings comprisingcooperating clutch elements associated with the parts to be coupled, re-

. spectively, and means for readily disengaging each of the couplings.

7. In an aircraft having two separate control systems each of whichcomprisesa control member, power transmission and a control surface, adisengageable coupling directly operative between the powertransmissions of the two systems at a point intermediate the controlmembers and the control surfaces, a disengageable coupling mem.

ber between the control members, and a disen-y gageable couplingdirectly operative between the control surfaces, said couplingscomprising cooperating clutch elements associated with the parts to becoupled, respectively, and means for readily disengaging each of thecouplings.

-8. In an aircraft having two separate control systems each of whichcomprises a control member, a plurality of pairs of duplicate controlsurfaces and power transmission mechanism betweenV each control memberand one duplicate control surface of each pair, a disengageable couplingdirectly operative between the duplicate control surfaces of each pair,and a disengageable coupling directly operative between the controlmember of each system, said couplings comprising cooperating clutchelements associated with the parts to be coupled, respectively, andmeans A lcontrol members and the control surfaces whereby all controlsurfaces may be operated from one control member on breakage of thetransmission mechanism extending from the other. ,p

amen' wom..-

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